There are a few ahadeeth that i dont understand how they are reconciled in saheeh al bulhari and i wondered if someone can explain inshallah?

they are both narrated by ayesha radiyallahu anha and one states that the prophet salallahu alayhi wasalam used to pray 13 rak'ah including taraweeh, witr and the sunnah of fajr, and one states that the prophet salallahu alayhi wasalam used to offer 13 raka'ah in the night prayer and on hearing the adhaan for fajr, he use to offer two light raka'ah.

also i would like to know if witr and tahajudd are the same prayer? So if i aim to start establishing tahajudd prayer every night, but sometimes i only pray one rak'ah after isha, have i prayed tahajudd?